EGUsphere EGUsphere EGUsphere EGUsphere Copernicus Publications GΓΆttingen, Germany 10.5194/egusphere-2025-1703 Comment on "Weibel instability in a plasma with nonzero external magnetic field" by O. A. Pokhotelov and M. A. Balikhin, Ann. Geophysicae, 30, 1051–1054, (2012) Naceur Rebiha 1 Sid Abdelaziz 1 Malim Roumaissa 1 Firouzi-Farashbandi Narges 2 Laboratory of Physics of Radiations and their Interactions with Matter, University of Batna 1, 05000, Batna, Algeria Department of Physics Education, Farhangian University, Taheran, Iran 28 04 2025 2025 1 8 Copyright: © 2025 Rebiha Naceur et al. 2025 This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/ This article is available from https://egusphere.copernicus.org/preprints/2025/egusphere-2025-1703/ The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2025/egusphere-2025-1703/egusphere-2025-1703.pdf

In the reference (Ann. Geophysicae, 30, 1051&ndash;1054, (2012)), the dispersion relation of Weibel modes is explicitly calculated in magnetized plasma. The parameters of Weibel instability which are the Weibel mode frequency, 𝑅𝑒(πœ”), and the growth rate of the Weibel instability, πΌπ‘š(πœ”) are deduced from the obtained dispersion relation under justified approximations.</p> <p>Several errors, which affect the results, are identified in this reference (Ann. Geophysicae, 30, 1051&ndash;1054, (2012)). We are interested in the present work to correct these errors.</p> <p>It has been shown that πΌπ‘š(πœ”) remains the same that in the case of zero external magnetic field. However, 𝑅𝑒(πœ”), is proportional to the electron cyclotron frequency, ~ βˆ“ πœ”π‘ , and to the temperature anisotropy, ~ <span style="border-bottom: 1px solid #000; vertical-align: 50%; font-size: .7em; color: #000;">βˆ†<em>T</em></span><span style="margin-left: -1.3em; margin-right: .5em; vertical-align: -35%; font-size: .7em; color: #000;"><em>T</em><sub>βˆ₯</sub></span> = <span style="border-bottom: 1px solid #000; vertical-align: 50%; font-size: .7em; color: #000;"><em>T</em><sub>&perp;</sub> &minus; <em>T</em><sub>βˆ₯</sub></span><span style="margin-left: -1.3em; margin-right: .5em; vertical-align: -35%; font-size: .7em; color: #000;"><em>T</em><sub> βˆ₯ </sub></span> = (<span style="border-bottom: 1px solid #000; vertical-align: 50%; font-size: .7em; color: #000;"><em>T</em><sub>&perp;</sub></span><span style="margin-left: -1.3em; margin-right: .5em; vertical-align: -35%; font-size: .7em; color: #000;"><em>T</em><sub>βˆ₯</sub></span> &minus; 1), where <em>T</em><sub>&perp;</sub> and <em>T</em><sub>βˆ₯</sub> are respectively the perpendicular and the parallel temperature.